The most common type of total anomalous pulmonary venous connection is

Most common type of TAPVC is supracardiac type,where 2 pulmonary vein join to form common pulmonary vein that may drains to left innominate vein or right superior venacava. Classification of TAPVC : Darling&;s classification (1957) is the most popular. 1. Type I-Supracardiac connections : 45% of TAPVC patients.The common venous confluence joins SVC. 2. Type II-Cardiac TAPVC It accounts for 25% of cases.CVC drains into coronary sinus or directly into RA. 3. Type III-Infracardiac TAPVC Approx.21% of cases.CVC drains into hepatic vein,ductus venosus,poal vein or IVC.The common pulmonary vein penetrates the diaphragm through the esophageal hiatus. 4. Type IV-Mixed Type It accounts for <10% of cases. Ref : Ghai essential of pediatrics, eighth edition, p.no:426